scholarly journals Ultrastructural changes and cyclic AMP in frog oxyntic cells.

1978 ◽  
Vol 76 (1) ◽  
pp. 31-42 ◽  
Author(s):  
K S Carlisle ◽  
C S Chew ◽  
S J Hersey
Keyword(s):  
Cyclic Amp ◽  
Acid Secretion ◽  
Surface Area ◽  
Acid Production ◽  
Morphological Changes ◽  
Membrane Surface ◽  
Ultrastructural Changes ◽  
H2 Receptor Antagonist ◽  
Histamine H2 Receptor

In vitro frog gastric mucosa was employed as a model for a combined physiological, biochemical, and ultrastructural study of the morphological changes which accompany the onset of acid secretion by the oxyntic cell. The histamine H2-receptor antagonist metiamide was used to provide a reproducible control state. Stimulation of acid production by theophylline resulted in a 10-fold increase in plasma membrane surface area and a distinct change in the conformation of mitochondrial cristae. Studies using the acid secretion inhibitors, thiocyanate and anoxia, demonstrated that neither acid production per se nor oxidative metabolism is essential for the theophylline-dependent changes in surface area. Increases in tissue cyclic AMP levels were observed under the conditions producing morphological changes. It is postulated that surface area changes induced by theophylline are controlled by cellular cyclic AMP levels.

Secretagogue-specific effects of interleukin-1 on gastric acid secretion

1991 ◽  
Vol 261 (4) ◽  
pp. G559-G564 ◽  
Author(s):  
J. L. Wallace ◽  
M. Cucala ◽  
K. Mugridge ◽  
L. Parente
Keyword(s):  
Acid Secretion ◽  
Gastric Acid Secretion ◽  
Gastric Acid ◽  
Interleukin 1 ◽  
Tnf Alpha ◽  
Inhibitory Effects ◽  
H2 Receptor Antagonist ◽  
Histamine H2 Receptor ◽  
Specific Effects ◽  
Bilateral Vagotomy

Interleukin-1 beta (IL-1 beta) has recently been shown to reduce the severity of experimental gastroduodenal damage and to inhibit acid secretion in the pylorus-ligated rat. In the present study, the effects of IL-1 beta on pentagastrin-stimulated acid secretion were compared with those of two other cytokines, namely IL-1 alpha and tumor necrosis factor (TNF) alpha. Also, the effects of IL-1 beta on gastric acid secretion stimulated by bethanechol or histamine were assessed. Anesthetized rats were pretreated intravenously with one of the cytokines, at doses in the 0.1-5 micrograms/kg range, 30 min before starting an intravenous infusion of pentagastrin. TNF alpha failed to significantly affect acid secretion, whereas IL-1 alpha and IL-1 beta exhibited significant inhibitory effects. For example, at a dose of 5 micrograms/kg, IL-1 alpha and IL-1 beta reduced acid secretion by 33 and 80%, respectively. The inhibitory effects of IL-1 beta on acid secretion could be completely inhibited by preincubation with an antibody directed against IL-1 beta but not by pretreatment with indomethacin (5 mg/kg sc) or by bilateral vagotomy. If acid secretion was stimulated by intravenous infusions of histamine or bethanechol, neither IL-1 beta nor TNF alpha produced significant inhibitory effects. Inhibition of acid secretion by IL-1 was also observed when the IL-1 was administered subsequent to stimulation by pentagastrin administration. These results demonstrate that IL-1 beta is an extremely potent inhibitor of acid secretion stimulated by pentagastrin but not that stimulated by histamine or bethanechol, through a mechanism that is at least in part independent of the vagus nerve and of prostaglandin synthesis. IL-1 alpha is less potent as an inhibitor of gastric acid secretion, whereas TNF appears to be inactive. Because pentagastrin-stimulated acid secretion could be completely inhibited by a histamine H2-receptor antagonist (cimetidine) and because IL-1 had no effect on histamine-stimulated acid secretion, it is possible that IL-1 exerts its antisecretory actions by inhibiting pentagastrin-stimulated histamine release.

Effect of a histamine H2-receptor antagonist on immunologically induced mediator release in vitro

1974 ◽  
Vol 4 (5) ◽  
pp. 297-303 ◽  
Author(s):  
L. W. Chakrin ◽  
R. D. Krell ◽  
J. Mengel ◽  
D. Young ◽  
C. Zaher ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Mediator Release ◽  
H2 Receptor Antagonist ◽  
Histamine H2 Receptor ◽  
H2 Receptor ◽  
Release In Vitro ◽  
Histamine H2 Receptor Antagonist

In vitrocytokines profile and ultrastructural changes of microglia and macrophages following interaction withLeishmania

Parasitology ◽  
2014 ◽  
Vol 141 (8) ◽  
pp. 1052-1063 ◽  
Author(s):  
PATRICIA KARLA SANTOS RAMOS ◽  
MAYSA DE VASCONCELOS BRITO ◽  
FERNANDO TOBIAS SILVEIRA ◽  
CLÁUDIO GUEDES SALGADO ◽  
WANDERLEY DE SOUZA ◽  
...  
Keyword(s):  
Immune Responses ◽  
Parasite Species ◽  
Morphological Changes ◽  
Expression Patterns ◽  
Ultrastructural Changes ◽  
American Cutaneous Leishmaniasis ◽  
Causative Agents ◽  
Infected Cells ◽  
Robust Response

SUMMARYIn the present study, we assessed morphological changes and cytokine production afterin vitrointeraction with causative agents of American cutaneous leishmaniasis and compared the microglia and macrophage immune responses. Cultures of microglia and macrophages infected with stationary-phase promastigotes ofLeishmania(Viannia)shawi, Leishmania(Viannia)braziliensisorLeishmania(Leishmania)amazonensiswere evaluated 24, 48 and 72 h after interaction. Macrophages only presented the classical phagocytic process while microglia also displayed large cytoplasmic projections similar to the ruffles described in macropinocytosis. In the macrophage cultures, the percentage of infected cells increased over time, in a fashion that was dependent on the parasite species. In contrast, in microglial cells as the culture time progressed, there was a significant reduction in the percentage of infected cells independent of parasite species. Measurements of cytokines in macrophage cultures 48 h after interactions revealed distinct expression patterns for different parasites, whereas in microglial cultures they were similar for allLeishmaniatested species. Taken together, our results suggest that microglia may have a higher phagocytic ability and cytotoxic potential than macrophages for all investigated species. The robust response of microglia against all parasite species may suggest microglia have an important role in the defence against cerebral leishmaniasis.

scholarly journals GAMBARAN HISTOPATOLOGIK MUKOSA LAMBUNG TIKUS PUTIH (Rattus norvegicus) YANG DIINDUKSI KEBISINGAN DAN DIBERIKAN RANITIDIN

2013 ◽  
Vol 1 (2) ◽  
Author(s):  
Patricia Sembor
Keyword(s):  
Gastric Acid ◽  
Acid Production ◽  
H2 Receptor Antagonist ◽  
Histamine H2 Receptor ◽  
Acute Gastritis ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Gastric Mucous ◽  
Group 1

Abstrak: Bising memegang peranan yang sangat besar dalam menyebabkan stres. Stres bisa meningkatkan produksi asam lambung. Ranitidin merupakan obat untuk saluran cerna yang menghambat reseptor H2 secara selektif dan reversibel dalam meningkatkan produksi asam lambung. Tujuan penelitian untuk mengetahui pengaruh kebisingan terhadap gambaran histopatologik mukosa lambung dan efek pemberian ranitidin terhadap gambaran histopatologik mukosa lambung tikus wistar yang diinduksi kebisingan. Penelitian eksperimental ini dilakukan selama 5 bulan dengan menggunakan 25 ekor tikus wistar yang dibagi dalam 5 kelompok (masing-masing terdiri dari 5 ekor tikus). Kelompok 1 adalah kontrol negatif (KN). Kelompok 2 (P1) diinduksi bising selama 12 hari. Kelompok 3 (P2) diinduksi bising dan diberikan ranitidin secara bersamaan selama 12 hari. Kelompok 4 (P3) diinduksi bising selama 12 hari dan tidak mendapat perlakuan apapun pada 7 hari berikutnya. Kelompok 5 (P4) diinduksi bising selama 12 hari dan diberikan ranitidin pada 7 hari berikutnya. Bising diberikan dengan intesitas 90-95 dB selama 8 jam sehari. Ranitidin diberikan dengan dosis 0,9mg/hari. Hewan uji diterminasi dengan cara dekapitasi, kemudian organ lambung diambil dan diproses untuk dibuat preparat histologi dengan pengecatan HE. Analisis histopatologik dilakukan dengan menggunakan mikroskop cahaya di laboratorium Fakultas Kedokteran Universitas Sam Ratulangi Manado. Kelompok KN memberikan gambaran mikroskopik lambung normal. Kelompok P1, P3, dan P4 secara mikroskopik menunjukkan hasil yang hampir sama, yakni infiltrasi sel radang PMN, edema, dan vasodilatasi pembuluh darah pada mukosa lambung. Kelompok P2 menunjukkan infiltrasi sel radang PMN, edema dan vasodilatasi yang lebih sedikit dibandingkan dengan kelompok yang lain. Tikus yang diinduksi kebisingan menunjukkan tanda-tanda gastritis akut secara histopatologik. Pemberian ranitidin bersamaan dengan induksi kebisingan lebih baik dibandingkan dengan pemberian ranitidin setelah induksi kebisingan dalam terapi gastritis akibat stres oleh kebisingan. Kata kunci: bising, gastritis, ranitidin.   Abstract: Noise has a big role in causing stress. Stress can increase gastric acid production. Ranitidine is a selective and reversible histamine H2-receptor antagonist that inhibits gastric acid production. The objectives of this research were to study the histopathology of noise-exposed gastric mucous and the effects of ranitidine on histopathology noise-exposed gastric mucous. This study was an experimental research. The research was conducted in 5 months. 25 healthy rats were divided into 5 groups, 5 rats for each group. Group 1 (KN) was a controlled group. Group 2 (P1) was exposed by noise in 12 days. Group 3 (P2) was exposed by noise and ranitidine in 12 days. Group 4 (P3) was exposed by noise in 12 days and not given any treatment for the next 7 days. Group 5 (P4) was exposed by noise in 12 days and ranitidine for the next 7 days. Noise was given with the intensity of 90-95 decibel. Ranitidine was given with doses of 0.9 mg/day. The data collection was conducted after the latest treatment for each group by taking out the gastric of the sacrificed rats. Gastric microscopic slides were prepared using paraffin method and stained with hematoxylin eosin staining. Gastric specimen was studied using light microscopy. Group 1 showed a normal histology of gastric. Group 2, 4, and 5 showed the infiltration of polymorph nuclear leukocytes (PMN) cell, edema, and vasodilatation on the gastric mucous. Group 3 showed less infiltrations of polymorph nuclear leukocytes (PMN) cell, edema, and vasodilatation on the gastric mucous compared to the other 3 groups. Histopathology study showed that signs of acute gastritis present in the noise-exposed gastric mucous. Ranitidine treatment together with the noise exposed still showed the signs of acute gastritis although less PMN cell present. Keywords: gastritis, noise, ranitidine.

scholarly journals Altered Na+/K+-ATPase expression plays a role in rumen epithelium adaptation in sheep fed hay ad libitum or a mixed hay/concentrate diet

2011 ◽  
Vol 56 (No. 1) ◽  
pp. 36-48 ◽  
Author(s):  
J. Kuzinski ◽  
R. Zitnan ◽  
T. Viergutz ◽  
J. Legath ◽  
M. Schweigel
Keyword(s):  
Cell Membrane ◽  
Mrna Expression ◽  
Surface Area ◽  
Morphological Changes ◽  
Membrane Surface ◽  
Membrane Surface Area ◽  
Cell Layers ◽  
Ad Libitum ◽  
Atpase Localization ◽  
Cell Membrane Surface

In this study we investigated rumen papillae morphology and the localization and expression of the<br />Na<sup>+/</sup>K<sup>+</sup>-ATPase&nbsp;in eight sheep fed hay ad libitum (h) or hay ad libitum plus additional concentrate (h/c). Four sheep were provided with the ad libitum h-diet for the complete three-week experimental period. The second group of four sheep received the h-diet for only one week and was fed the mixed hay/concentrate (h/c) diet for another two weeks. The amount of concentrate supplement was stepwise increased from 150 to 1000 g/day and given in two meals. Following slaughter rumen papillae from the atrium ruminis (AR), the rumen ventralis (RV) and the ventral blind sac (BSV) were fixed and examined for morphological changes and Na<sup>+</sup>/K<sup>+</sup>-ATPase localization by morphometric methods and immunohistochemistry. Ruminal epithelial cells (REC) originating from the strata basale to granulosum were also isolated. Cellular Na<sup>+</sup>/K<sup>+</sup>-ATPase expression (mRNA and protein) and differentiation state were determined by RT-PCR, Western blot, and flow cytometry. Compared with data from h-fed sheep, morphometric analysis revealed an increased length and width of rumen papillae in h/c-fed sheep, resulting in a marked 41% and 62% increase in rumen papillae surface in AR and RV, respectively. The rumen mucosa of h/c-fed sheep was characterized by a predominant stratum corneum (42 &plusmn; 0.7 &micro;m vs. 28 &plusmn; 0.5 &micro;m), but the thickness of the metabolically active cell layers remained unchanged. REC suspensions from sheep fed the h/c diet generally contained more cells (7.30 &plusmn; 0.83 vs. 3.49 &plusmn; 0.52 &times; 10<sup>7</sup>/ml; P &lt; 0.001) and an increased proportion of REC positive for basal cytokeratin and for the differentiation marker cytokeratin 10 (P &lt; 0.05). Cellular (cell membrane) and epithelial (stratum basale to stratum granulosum) Na<sup>+</sup>/K<sup>+</sup>-ATPase localization was similar between rumen regions and was not changed by concentrate feeding. After two weeks on the h/c-diet, a 96% increase in the absolute number of Na<sup>+</sup>/K<sup>+</sup>-ATPase-positive REC (6.56 &plusmn; 0.84 vs. 3.35 &plusmn; 0.51 &times; 10<sup>7</sup>/ml; P = 0.003) and a 61% elevation (P = 0.043) in Na<sup>+</sup>/K<sup>+</sup>-ATPase protein expression in REC from the upper third of the suprabasal cell layers were found. Moreover, a two-fold (P = 0.001) elevation in cell membrane surface area accompanied by a reduction (1.19 &times; 10<sup>&ndash;7</sup> &plusmn; 1.72 &times; 10<sup>&ndash;9</sup> arbitrary units (AU)/cm2 vs. 1.73 &times; 10<sup>&ndash;7</sup> &plusmn; 8.16 &times; 10<sup>&ndash;9</sup> AU/cm<sup>2</sup> in the h-group; P &lt; 0.001) in specific Na<sup>+</sup>/K<sup>+</sup>-ATPase fluorescence per cm<sup>2</sup> of cell membrane surface area was observed after h/c-feeding. Na<sup>+</sup>/K<sup>+</sup>-ATPase &alpha; subunit mRNA expression was also reduced (P &lt; 0.0001) from 0.154 &plusmn; 0.013 to 0.057 &plusmn; 0.004 pg per pg S18 mRNA control in the h/c-compared with the h-group. Thus, the h/c-diet led to a rapid increase in REC number and total cell membrane surface area in metabolically active and resorptive cell layers and was accompanied by a reduction in Na<sup>+</sup>/K<sup>+</sup>-ATPase mRNA expression and abundance per cell membrane surface area.

Ultrastructural changes in chloroplasts resulting from fluctuations in NaCl concentration: freeze-fracture of thylakoid membranes in Dunaliella salina

1975 ◽  
Vol 18 (2) ◽  
pp. 287-299 ◽  
Author(s):  
A.O. Pfeifhofer ◽  
J.C. Belton
Keyword(s):  
Salt Concentration ◽  
Dunaliella Salina ◽  
Unit Area ◽  
Morphological Changes ◽  
Membrane Surface ◽  
Freeze Fracture ◽  
Thylakoid Membranes ◽  
Ultrastructural Changes ◽  
Thin Sections ◽  
Number Of Particles

The structure of chloroplasts isolated from Dunaliella salina has been studied with respect to changing concentrations of sodium chloride in the culture medium. Freeze-fracture replicas and thin sections of intact chloroplasts do not exhibit any noticeable changes in structure at concentrations ranging between 3.5 and 25% NaCl. Chloroplasts isolated from algal cells that have been acclimatized to the higher salt concentration show a change in the thylakoid membranes. The thylakoid membranes appear compressed over a major portion of the membrane surface, with only the end of the thylakoid membranes unappressed. The number of particles per unit area on the B face is also altered by the salt concentration. The chloroplasts acclimatized to 25% NaCl have about 3 times the number of particles per unit area on a B face of end-membranes as on a comparable face of thylakoid membranes acclimatized to low (3.5% NaCl) salt concentration. These morphological changes can be reversed if the chloroplasts acclimatized to high or low salt concentrations are returned to a medium of different salt concentration prior to freeze-fracturing.

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